Fuel composition

ABSTRACT

A gasoline composition containing, as an anti-wear additive, an aliphatic diether of diethylene glycol, or a combination of the glycol and a dialkyl ester of phthalic acid.

United States Patent Dorsch 1 May 2,1972

[54] FUEL COMPOSITION [72] Inventor: Erwin A. Dorsch, Fox River Grove, Ill.

[73] Assignee: Union Oil Company of California, Los Angeles, Calif.

[22] Filed: Feb. 17, 1969 [21] Appl. No.: 802,739

. [52] US. Cl ..44/58, 44/69, 44/70,

1 44/77 511 Int.Cl. ..c10|1/1s,c1o11 s0 58 Field of Search... ..44/56, 69, 70, 77, 58; 252/52 [56] References Cited FOREIGN PATENTS OR APPLICATIONS 709,987 6/1954 Great Britain ..44/56 766,591 1/1957 997,906 7/ l 965 635,722 l/l962 Great Britain Great Britain..... Canada ..44/ 69 [5 7] ABSTRACT A gasoline composition containing, as an anti-wear additive, an aliphatic diether of diethylene glycol, or a combination of the glycol and a dialkyl ester of phthalic acid.

12 Claims, No Drawings FUEL COMPOSITION This invention relates to a gasoline composition containing additives that reduce the wear of the parts of an internal combustion engine.

The dimensional changes of critical parts, such as bearings, cam lobes, cylinders, pistons, and piston rings limit the useful life of an internal-combustion engine. Engine life has been extended by improved metallurgy, new metal alloys, improved lubricating-oil compositions, thermostatic temperature control, crankcase ventilation, and more recently, fuel additives. With the advent of high-compression, high-r.p.m., high-torque engines, the dimensional clearances of the parts were greatly reduced, and the influence of dimensional changes on engine performance and engine life have been amplified, particularly wear caused by the abrasive action of dust particles in the engme.

It is therefore an object of the invention to provide a gasoline composition that reduces engine wear.

It has now been found that this objective is achieved by incorporation of a small amount, i.e., from about to pounds per thousand barrels, of an aliphatic diether of diethylene glycol in the gasoline.

The diether has the formula ROCH CH OCH CH OR in which R and R are aliphatic radicals. Compounds in which R and R are straight-chain alkyl radicals of about one to eight carbon atoms have been found particularly effective; however, compounds containing branched or substituted radicals may also be used. The dibutyl compound, employed in the examples below, is a preferred compound. Other suitable compounds are the diethyl, dioctyl, ethyl hexyl, methyl pentyl compounds, etc.

The antiwear properties of the compositions of the invention are achieved by using very small amounts of the additive, i.e., from about 5 to about 20'pounds per thousand barrelsof gasoline and the compositions are thus economical as well as effective in inhibiting wear. Optimum amounts of additive will depend on a variety of factors, such as the type of gasoline base, intended use. of the composition, other additives, etc., and are best determined experimentally.

The gasoline base employed in the compositionof the invention is a conventional fuel containing normal, branched chain and cyclic hydrocarbonsboiling in the range of about 90 to 425 F. They may be naturally occuring mixtures or may be prepared by conversion of other hydrocarbon mixtures. A preferred gasoline composition contains a-major proportion of the gasoline hydrocarbons prepared by fluid catalytic cracking and a minor proportion of'an alkylate prepared from isobutane and C and/0r C, olefins. More specifically, the base fuel (as typified by gasoline used in the example below) may comprise about 80 percent of gasoline from the fluid catalytic-cracking process and about20 percent of the aforementioned alkylate, with or without the addition of about 2 to 4 ml TEL/gal. Other metal compounds and other lead alkyls, or combinations thereof, may also be used in the compositionsofthe invention.

It has also beenfound that the'antiwear properties of the compositions of the invention are even furtherenhanced by the synergistic action of a second antiwear compound, i.e., a dialkyl ester of phthalic acid, in combination with the glycol ether. Estershaving alkyl groups of about one to eight carbon atoms are preferred. Dibutyl phthalate, the wear inhibiting properties of which are disclosed in US. Pat. No. 3,232,724, has been found to be particularly effective. The combination additive composition consists of about 10 to 90 weight percent ofthe glycol ether and about 90 to 10 percent ofthe ester.

The invention will be more specifically illustrated by means of the following example.

Effectiveness of dibutyl Carbitol (dibutyl ether of diethylene glycol), dibutyl phthalate and combinations of the two as-antiwear gasoline additives was studied using two single-cylinder COT engines having radioactive top compression rings. A cyclic temperature test method of the type disclosed in US. Pat. No. 3,232,724 was employed, in which the temperature was cycled between 60 F. and 210 F. every 30 minutes. The base fuel was -a premium gasoline of the type described above containing 3 cc. of tetraethyl lead (TEL) per gallon. After 4 hours of operation the radioactivity of the lubricating oil was measured by electronic means. The number of signals, due to radioactive-iron particles in the oil, gave a measure of theextent of wear. The difference in wear between base fuel and additive-containing fuel was reflected in the difference in counts picked up by the electronic ratemeter from the respective lubricating oils. The results are shown in the following table.

The radioactive counts shown are directly comparable-for consecutive tests in thesame engine and represent relative wear. The number of counts is a function of radioactive decay (time sinceirradiation), counting geometry and counting equipment. Thus tests run in different engines, with different counting systems, at different times, may show different count levels for the same amount of wear. This variation, however, cancels out when results are expressed as relative wear (or percent wear reduction).

Additives Radioactive (lb./l000 bbls.) Counts dibutyl dibutyl base base fuel reduction engine Carbitol phthalate fuel plus in wear by additive additive( s) It will be noted that 7 to 10 pounds of dibutyl Carbitol in late/ 1 ,000 bbls., gives wear reduction superior to 10 pounds of dibutyl phthalate or 10 pounds of dibutyl Carbitol alone.

The gasoline'compositions of the inventionmay also contain other conventional gasoline additives such" as anti oxi dants, anti-rust agents, detergents, deposit modifiers, antiicing agents, dyes, etc.

I claim:

1. An internal combustion engine fuel comprisinghydrocarbons boiling in the gasoline range and a minonproportion, sufficient-to reduce engine wear but less than 20 pounds per thousand barrels of fuel, of a dialkyl diether of diethylene glycol.

2. The fuel of claim 1 wherein the proportion of said diether is not more than about 10 pounds per thousand barrels of fuel.

3. The fuel of claim 1 wherein the proportion of said diether is greaterthan about 5 pounds per thousand barrels offuel.

4; The fuel of claim 1 in which the alkyl groups of the diether each have from one to eight carbon atoms.

5. Thefuel of claim 1 in which said diether isthe dibutyl ether.

6. The fuel of claim 1 additionally containing an anti-knock quantity of lead tetraethyl.

7. An internal combustion engine fuel comprising (1) hydrocarbons boiling in the gasoline range, (2) a minor proportion, sufficient to reduce engine wear but less than 20 pounds per thousand barrels of fuel, of an aliphatic diether of diethylene glycol, and (3) a dialkyl ester of phthalic acid in a minor amount sufficient to further enhance the a anti-wear characteristics of the fuel.

8. The fuel of claim 7 wherein the proportion of said diether isnot more than about 10 pounds per thousand barrels 'offuel.

9. The fuel of claim 7 wherein the proportion of said diether is greaterthan about'S pounds per thousand barrels of fuel.

10. The fuel of claim 7 wherein the alkyl groups of said dialkyl ester and said aliphatic diether each have from one to eight carbon atoms.

11. The fuel of claim 7 wherein said aliphatic diether is the dibutyl ether, and said dialkyl ester is the dibutyl phthalate. 5

12. The fuel of claim 7 additionally containing an antiknock quantity of lead tetraethyl. 

2. The fuel of claim 1 wherein the proportion of said diether is not more than about 10 pounds per thousand barrels of fuel.
 3. The fuel of claim 1 wherein the proportion of said diether is greater than about 5 pounds per thousand barrels of fuel.
 4. The fuel of claim 1 in which the alkyl groups of the diether each have from one to eight carbon atoms.
 5. The fuel of claim 1 in which said diether is the dibutyl ether.
 6. The fuel of claim 1 additionally containing an anti-knock quantity of lead tetraethyl.
 7. An internal combustion engine fuel comprising (1) hydrocarbons boiling in the gasoline range, (2) a minor proportion, sufficient to reduce engine wear but less than 20 pounds per thousand barrels of fuel, of an aliphatic diether of diethylene glycol, and (3) a dialkyl ester of phthalic acid in a minor amount sufficient to further enhance the a anti-wear characteristics of the fuel.
 8. The fuel of claim 7 wherein the proportion of said diether is not more than about 10 pounds per thousand barrels of fuel.
 9. The fuel of claim 7 wherein the proportion of said diether is greater than about 5 pounds per thousand barrels of fuel.
 10. The fuel of claim 7 wherein the alkyl groups of said dialkyl ester and said aliphatic diether each have from one to eight carbon atoms.
 11. The fuel of claim 7 wherein said aliphatic diether is the dibutyl ether, and said dialkyl ester is the dibutyl phthalate.
 12. The fuel of claim 7 additionally containing an anti-knock quantity of lead tetraethyl. 